Wireless communication device having conductive elements antenna

ABSTRACT

An antenna coupled to a wireless communication device is comprised of a conductive component, such as a series of conductive elements, that forms a conductor if placed under a threshold force. The conductor is coupled to the wireless communication device so that the wireless communication device is capable of communicating at an operating frequency defined by the length and construction of the conductor. By communicating using the conductor as an antenna, the wireless communication device may provide an indication of force to an interrogation reader. Furthermore, a conductive support element, such as a tuning ring, may be used for communication as well as coupling the conductive component to the wireless communication device. Multiple conductive components may be coupled to the wireless communication device for communicating at multiple frequencies if placed under multiple threshold forces.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 12/489,347,filed Jun. 22, 2009, now U.S. Pat. No. 7,843,393, which is a division ofU.S. application Ser. No. 11/838,147, filed Aug. 13, 2007, now U.S. Pat.No. 7,557,767, which is a continuation of U.S. application Ser. No.11/515,482, filed Aug. 31, 2006, now U.S. Pat. No. 7,327,326, which is acontinuation of U.S. application Ser. No. 10/422,637, filed Apr. 24,2003, now U.S. Pat. No. 7,239,287, which claims the benefit of U.S.Provisional Patent Application No. 60/375,248, filed Apr. 24, 2002, allof which are incorporated by reference herein in their entirety.

FIELD OF INVENTION

The present invention relates to a wireless communication device that iscoupled to a plurality of conductive elements that form an antenna whenplaced under a force.

BACKGROUND OF INVENTION

Wireless communication devices are commonly used today to wirelesslycommunicate information about goods. For example, transponders may beattached to goods during their manufacture, transport, and/ordistribution to provide information, such as the good's identificationnumber, expiration date, date of manufacture or “born on” date, lotnumber, and the like. The transponder allows this information to beobtained unobtrusively using wireless communication without slowing downthe manufacturing, transportation, and/or distribution process.

Some goods involve environmental factors by design that are critical totheir manufacture and/or intended operation. An example of such a goodis a vehicle tire. A tire is designed to be placed under pressure tooperate properly. Too little pressure can cause a tire to be damaged bythe weight of a vehicle supported by the tire. Too much pressure cancause a tire to rupture. Tire pressure must be tested during themanufacturing process to ensure that the tire meets intended designspecifications. The tire pressure should also be within certain pressurelimits during use in order to avoid dangerous conditions. Knowledge ofthe tire pressure during the operation of a vehicle can be used toinform an operator and/or vehicle system that a tire has a dangerouspressure condition. The vehicle may indicate a pressure condition bygenerating an alarm or warning signal to the operator of the vehicle.

A pressure sensor can be provided in the tire and coupled to the vehicleusing a wired connection. However, the tire moves with respect to thevehicle during the vehicle's movement, and a wired connection may besusceptible to damage or a break thereby causing a failure in receivingpressure information from the pressure sensor. A wireless communicationdevice may be more advantageous to place in a tire to communicate tirepressure. A pressure sensor can be coupled to a wireless communicationdevice that is placed inside a tire to wirelessly communicate tirepressure without need for wired connections. However, the additionalcost of the wireless communication device in addition to the pressuresensor may be cost prohibitive.

Therefore, an object of the present invention is to provide a wirelesscommunication device that can determine and communicate certainenvironmental conditions, such as pressure, without the use and addedcost of a separate environmental sensor.

SUMMARY

The present invention relates to an antenna coupled to a wirelesscommunication device that is comprised of a series of conductiveelements that form a conductor if placed under a force. The conductor iscoupled to a wireless communication device to provide an antenna so thatthe wireless communication device is capable of communicating at anoperating frequency defined by the length and construction of theconductor. The wireless communication device, through its communicationusing the conductor as an antenna, acts as an indicator of force to aninterrogation reader since the wireless communication device is notcapable of communicating to the interrogation reader unless a force isplaced on the series of conductive elements that form the antenna.

In one embodiment, the series of conductive elements are comprised oflinks that form a link chain. The link chain is coupled to the wirelesscommunication device to form a dipole antenna. The wirelesscommunication device and link chain are also attached to a flexible,resilient material. If a force is applied to the flexible materialand/or the link chain, the links in the link chain form conductiveconnections with each other to form an antenna to be used by thewireless communication device for wireless communication.

In another embodiment, the series of conductive elements are comprisedof hollow conductive spheres that join together using shaped links. Theshaped links form conductive connections between the hollow conductivespheres if a force is applied to the hollow conductive spheres and/or aflexible material containing the hollow conductive spheres.

In another embodiment, the series of conductive elements are coupled toa wireless communication device that are placed on the inside of a tireto act as a pressure indicator.

In another embodiment, the wireless communication device is coupled to aseries of conductive elements that are attached to a load to act as aweight indicator.

In another embodiment, the wireless communication device is coupled to aseries of conductive elements that is attached to an axle to act as arotation speed indicator.

In another embodiment, the wireless communication device is coupled to atuning ring, and the tuning ring is coupled to a series of conductiveelements. The tuning ring acts as a first antenna to allow the wirelesscommunication device to operate at a first operating frequency. Theseries of conductive elements acts as a second antenna if placed under aforce to allow the wireless communication device to operate at a secondoperating frequency.

In another embodiment, the wireless communication device is coupled to aseries of conductive elements that contains a moveable link. The seriesof conductive elements acts as a first antenna having a first length ifthe moveable link is not under a force to allow the wirelesscommunication device to operate at a first operating frequency. Theseries of conductive elements acts as a second antenna having a secondlength if the moveable link is under a force to allow the wirelesscommunication device to operate at a second operating frequency.

In another embodiment, the wireless communication device is coupled to afixed conductor that is coupled to a series of conductive elements. Thefixed conductor acts as a first antenna regardless of any force appliedto the series of conductive elements to allow the wireless communicationdevice to operate at a first operating frequency. The series ofconductive elements couple to the fixed conductor to become oneconductor acting as a second antenna if the series of conductiveelements are under a force to allow the wireless communication device tooperate at a second operating frequency.

In another embodiment, the wireless communication device is coupled to aseries of conductive elements that includes a locking mechanism. Thewireless communication device is capable of using the series ofconductive elements as an antenna for wireless communication when thelocking mechanism is engaged, locking the series of conductive elementsin a conductive connection. The conductive connection remains even ifthe force is later removed from the series of conductive elements.

The interrogation reader may communicate information received from awireless communication device using the series of conductive elements asan antenna to a reporting system located in close proximity to theinterrogation reader, a remote system, or both.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of an interrogation reader and wirelesscommunication device system in the prior art;

FIG. 2A is a schematic diagram of a chain coupled to a wirelesscommunication device whose links are not under force;

FIG. 2B is a schematic diagram of a chain coupled to a wirelesscommunication device whose links are under force to form a conductor anda dipole antenna;

FIG. 3 is a schematic diagram of one embodiment of hollow conductivespheres in a chain that are designed to form a conductor if under force;

FIG. 4 is a flowchart diagram of an interrogation reader determiningthat a certain force or temperature threshold condition has been met atthe wireless communication device when the interrogation reader receivessuccessful communication from the wireless communication device;

FIG. 5 is a schematic diagram of a chain coupled to a wirelesscommunication device in a tire that forms an antenna when the tire isinflated to a certain pressure level;

FIG. 6 is a schematic diagram of a chain coupled to a load and to awireless communication device such that the chain forms an antenna whenthe load is above a certain weight;

FIG. 7 is a schematic diagram of a chain coupled to an axle and to awireless communication device such that the chain forms an antenna whenthe axle rotates above a certain speed;

FIG. 8 is a schematic diagram of a chain and a tuning ring coupled to awireless communication device such that the wireless communicationdevice can operate at a first operating frequency using the tuning ringas a first antenna and can operate at a second operating frequency usingthe chain as a second antenna;

FIG. 9 is a schematic diagram of a chain that has one moveable linkcoupled to a wireless communication device so that the wirelesscommunication device can communicate at a first operating frequency whenthe chain forms a first antenna and can communicate at a secondoperating frequency when a force is placed on the moveable link to forma second antenna;

FIG. 10 is a schematic diagram of a wireless communication devicecoupled to a fixed conductor to act as a first antenna to communicate ata first operating frequency and coupled to a chain to act as a secondantenna to communicate at a second operating frequency when a force isplaced on the chain;

FIG. 11A is a schematic diagram of conductive elements in a lockingmechanism that is in an unlocked position;

FIG. 11B is a schematic diagram of conductive elements in a lockingmechanism in a locked position wherein the conductive elements andlocking mechanism form a conductor to be used by a wirelesscommunication device as an antenna; and

FIG. 12 is a schematic diagram of a reporting system.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an antenna coupled to a wirelesscommunication device. The antenna is comprised of a series of conductiveelements that do not form conductive connections with each other to formthe antenna unless they are placed under a force, such as tension orcompression. If the conductive elements are placed under a force, theconductive elements form conductive connections with each other to forma conductor.

This conductor is coupled to a wireless communication device to providean antenna so that the wireless communication device is capable ofcommunicating at an operating frequency defined by the length andconstruction of the conductor. In this manner, the wirelesscommunication device, through its communication using the conductor asan antenna, acts as an indicator of force to an interrogation readersince the wireless communication device is not capable of communicatingunless the series of conductive elements are under a force. The wirelesscommunication device can be used in various applications as an indicatorof force.

Before discussing the particular aspects of the present invention andthe embodiments for providing a series of conductive elements to form aconductor and antenna if placed under a force, a brief discussion ofinterrogation readers and wireless communication devices follows.

FIG. 1 illustrates a typical wireless communication device andcommunication system in the prior art. The wireless communication device10 is capable of communicating information wirelessly and may include acontrol system 12, communication electronics 14, and memory 16. Thewireless communication device 10 is also known as a radio-frequencyidentification device (RFID). The communication electronics 14 iscoupled to an antenna 18 for wirelessly communicating information inradio-frequency signals. The communication electronics 14 is capable ofreceiving modulated radio-frequency signals through the antenna 18 anddemodulating these signals into information passed to the control system12. The antenna 18 may be internal or external to the wirelesscommunication device 10. The antenna 18 may be a pole antenna or a slotantenna.

The control system 12 may be any type of circuitry or processor thatreceives and processes information received by the communicationelectronics 14, including a micro-controller or microprocessor. Thewireless communication device 10 may also contain a memory 16 forstorage of information. Such information may be any type of informationabout goods or objects associated with the wireless communication device10, including but not limited to identification, tracking and otherpertinent information. The memory 16 may be electronic memory, such asrandom access memory (RAM), read-only memory (ROM), flash memory, diode,etc., or the memory 16 may be mechanical memory, such as a switch,dip-switch, etc.

Some wireless communication devices 10 are termed “active” devices inthat they receive and transmit data using their own energy sourcecoupled to the wireless communication device 10. A wirelesscommunication device 10 may use a battery for power as described in U.S.Pat. No. 6,130,602, entitled “Radio frequency data communicationsdevice,” or may use other forms of energy, such as a capacitor asdescribed in U.S. Pat. No. 5,833,603, entitled “Implantable biosensingtransponder.” Both of the preceding patents are incorporated herein byreference in their entirety.

Other wireless communication devices 10 are termed “passive” devices,meaning that they do not actively transmit and therefore may not includetheir own energy source for power. One type of passive wirelesscommunication device 10 is known as a “transponder.” A transpondereffectively transmits information by reflecting back a received signalfrom an external communication device, such as an interrogation reader.An example of a transponder is disclosed in U.S. Pat. No. 5,347,280,entitled “Frequency diversity transponder arrangement,” incorporatedherein by reference in its entirety. Another example of a transponder isdescribed in U.S. Pat. No. 6,501,435, entitled “Wireless communicationdevice and method,” incorporated herein by reference in its entirety.

It is readily understood to one of ordinary skill in the art that thereare many other types of wireless communication devices and communicationtechniques than those described herein, and the present invention is notlimited to a particular type of wireless communication device,technique, or method.

FIG. 1 also depicts communication between a wireless communicationdevice 10 and an interrogation reader 20. The interrogation reader 20may include a control system 22, an interrogation communicationelectronics 24, memory 26, and an interrogation antenna 28. Theinterrogation antenna 28 may be a pole antenna or a slot antenna. Theinterrogation reader 20 may also contain its own internal energy source30, or the interrogation reader 20 may be powered through an externalpower source (not shown). The energy source 30 may include a battery, acapacitor, solar cell, or other medium that contains energy. The energysource 30 may also be rechargeable. The interrogation reader 20 may alsoinclude a clock 23 that is coupled to and used by the control system 22for changing clock cycles and timing operations and/or other timingcalculations.

The interrogation reader 20 communicates with the wireless communicationdevice 10 by emitting an electronic communication signal 32 modulated bythe interrogation communication electronics 24 through the interrogationantenna 28. The interrogation antenna 28 may be any type of antenna thatcan radiate a communication signal 32 through a field 34 so that areception device, such as a wireless communication device 10, canreceive such communication signal 32 through its own antenna 18. Thefield 34 may be electro-magnetic, magnetic, or electric. Thecommunication signal 32 may be a message containing information and/or aspecific request for the wireless communication device 10 to perform atask or communicate back information.

When the antenna 18 is in the presence of the field 34 emitted by theinterrogation reader 20, the communication electronics 14 are energizedby the energy in the communication signal 32, thereby energizing thewireless communication device 10. The wireless communication device 10remains energized so long as its antenna 18 is in the field 34 of theinterrogation reader 20. The communication electronics 14 demodulatesthe communication signal 32 and sends the message containing informationand/or request to the control system 12 for appropriate actions.

Turning now to aspects of the present invention, FIG. 2A illustrates oneembodiment of the antenna 18 for the wireless communication device 10.The antenna 18 is comprised of a series of conductive elements that forma link chain 40. The link chain 40 is coupled to the wirelesscommunication device 10 to act as its antenna 18 when the link chain 40is under a force, such as tension or compression. In this embodiment,two link chains 40 are coupled to the wireless communication device 10at coupling points 41 to form a dipole antenna 18.

The link chain 40 is comprised of a plurality of individual links 42that are circular in shape. The links 42 are constructed out of aconductive material, such as aluminum, copper, or steel. The wirelesscommunication device 10 and the link chain 40 are attached to a flexiblematerial 43. The flexible material 43 is a resilient material that iscapable of flexing, such as stretching or compressing, when a force isplaced on the flexible material 43. The flexible material 43, beingresilient, returns back to its original shape when a force is notexerted on it. The flexible material 43 may be constructed out ofrubber, foam, or any material that is capable of being stretched orcompressed and is resilient. Note that the flexible material 43 isoptional, and force may be applied directly to the conductive elementsto allow the wireless communication device 10 to act as a pressureindicator.

The force exerted on the flexible material 43 may be an externalmechanical force, including gravity, or may be caused by the flexiblematerial's 43 response to an environmental condition, such astemperature. The flexible material may be any type of flexible materialso long as the material flexes.

The flexible material 43 illustrated in FIG. 2A is not under a force.The links 42 are attached to the flexible material 43 so that the links42 either (1) do not form a good conductive connection or (2) anyconductive connection whatsoever between each other when the flexiblematerial 43 is not under a force. The wireless communication device 10is designed to operate at a frequency that uses the link chain 40 as anantenna 18 when the link chain 40 is under a force. So even if there aresome links 42 in the link chain 40 that are conductively connected toeach other when the flexible material 43 is not under a force, theconductive length of the link chain 40 will be different than isintended for use by the wireless communication device 10 and/or theinterrogation reader 20 for their designed operating frequency.

FIG. 2B illustrates the same wireless communication device 10 and linkchain 40 illustrated in FIG. 2A, discussed above. However in FIG. 2B,the flexible material 43 is under a force; it is being stretched. Thisstretching causes the link chain 40 and its links 42 to stretch as wellsince the links 42 are attached to the flexible material 43. In thismanner, the links 42 come into contact with each other to form aconductor that is coupled to the wireless communication device 10, atthe couplings 41. When the links 42 form a conductor, the links 42 arecontinuously coupled to the wireless communication device 10 so that thewireless communication device 10 can use the links 42 as an antenna 18.

The links 42 in the link chain 40 may also be compressed by compressingthe flexible material 43 to form a conductor. If the links 42 arecompressed so that the links 42 come into conductive contact with eachother, the links 42 will form a conductor that can also be used by thewireless communication device 10 as an antenna 18. Compression of thelinks 42 will create an antenna 18 that is used to communicate at ahigher operating frequency than stretching of the links 42, sincecompression of the links 42 will form a conductor that is shorter inlength than a conductor formed by stretching of the links 42.

Whether the flexible material 43 and/or the links 42 are stretched orcompressed, the wireless communication device 10 is capable ofcommunicating using the link chain 40 as the antenna 18 at the desiredand designed operating frequency if the links 42 form a conductor. Whenthe interrogation reader 20 receives a communication signal 32 from thewireless communication device 10, illustrated in FIG. 2B, theinterrogation reader 20 will know that such successful communication isindicative of a threshold force being applied to the flexible material43 and/or the link chain 40.

FIG. 3 illustrates another embodiment of the present invention whereinthe antenna 18 is constructed out of different conductive elements thanthe links 42 illustrated in FIGS. 2A and 2B. The antenna 18 is comprisedof two or more hollow conductive spheres 44 that are attached to theflexible material 43. The hollow conductive spheres 44 may beconstructed of aluminum, steel, copper, or any other conductivematerial. The hollow conductive spheres 44 may be completely hollow orsubstantially hollow so long as the shaped links 48, discussed below, donot form a substantial conductive connection with the hollow conductivespheres 44 when the hollow conductive spheres 44 are not under a force.

Each hollow conductive sphere 44 contains two orifices 46. The orifices46 are located on the left-hand side and the right-hand side of eachhollow conductive sphere 44. Shaped links 48 are provided between eachhollow conductive sphere 44 to connect the hollow conductive spheres 44together to form a conductor when the hollow conductive spheres 44 arestretched. The shaped links 48 are constructed so that they have anarrow portion 50 in the central region of the shaped link 48 and widerportions 52 on each end of the shaped links 48. The wider portions 52have a larger diameter than the diameter of the orifices 46. In thismanner, the hollow conductive spheres 44 are free to move back-and-forthalong the path of the shaped link 48 as force is exerted on the hollowconductive spheres 44. However, the hollow conductive spheres 44 cannotmove farther apart than the length of the shaped link 48 since the widerportions 52 of the shaped links 48 are larger in diameter than theorifices 46.

When the flexible material 43 and/or the hollow conductive spheres 44are under tension, the hollow conductive spheres 44 move apart from eachother horizontally along the path of the shaped link 48 until the shapelength 48 reaches the point where the diameter of its wider portions 52reach the diameter size of the orifices 46. In this manner, a conductiveconnection is made between adjacent hollow conductive spheres 44 throughthe connectivity of the shaped links 48 to the adjacent hollowconductive spheres 44 through contact with the orifices 46.

The hollow conductive spheres 44 can also come into conductive contactwith each other when the flexible material 43 and/or the hollowconductive spheres 44 are compressed together. In this manner, thehollow conductive spheres 44 move closer to each other in a horizontaldirection along the path of the shaped link 48. Eventually, the shapedlink 48 between adjacent hollow conductive spheres 44 will be totallyinside the hollow conductive spheres 44, and the outside of adjacenthollow conductive spheres 44 will come into contact with each other toform a conductor.

Whether the flexible material 43 and/or the hollow conductive spheres 44are stretched or compressed, the hollow conductive spheres 44 willcreate a conductor to form an antenna 18 when the stretching orcompressing causes the hollow conductive spheres 44 to conductivelycontact each other to form a conductor. When the interrogation reader 20receives a communication signal from the wireless communication device10 using the antenna 18 formed by the hollow conductive spheres 44forming a conductor, the interrogation reader 20 will know that suchsuccessful communication is indicative of a defined force being appliedto the flexible material 43.

FIG. 4 illustrates a flowchart diagram of the process executed by theinterrogation reader 20 to determine if a wireless communication device10 in the range of its field 34 is under a force. The wirelesscommunication device 10 may use any antenna 18 that is a series ofconductive elements that form a conductor if the elements are under aforce, such as tension or compression. The wireless communication device10 may use an antenna 18, such as a link chain 40 or hollow conductivespheres 44, as illustrated in FIGS. 2 and 3 and discussed above.

The process starts (block 60), and the interrogation reader 20 sends outa communication signal 32 through the field 34 to establishcommunications with any wireless communication device 10 in the range ofthe field 34 (block 62). If the interrogation reader 20 does not receivea modulated signal response back from any wireless communication device10 (decision 64), this is indicative of one of two conditions; (1) thereis no wireless communication device 10 present in the range of the field34; or (2) a wireless communication device 10 in the range of the field34 is not under a force such that the conductive element coupled to thewireless communication device 10 forms a conductor to form an antenna18. In either condition, the interrogation reader 20 repeats by againsending out a communication signal 32 (block 62) in a looping manneruntil a modulated communication signal 32 response is received back froma wireless communication device 10.

If the interrogation reader 20 receives a response signal back from awireless communication device 10 (decision 64), this is indicative thatthe wireless communication device 10 is under a force since the wirelesscommunication device 10 is configured with an antenna 18 that does notform a conductor unless the antenna 18 is under a force. Theinterrogation reader 20 receives the communication from the wirelesscommunication device 10 and takes any action necessary and/or designedto be carried out (block 66). The interrogation reader 20 repeats theprocess by sending out a communication signal 32 to determine if eitherthe same wireless communication device 10 as was previously interrogatedis still under a force and/or if another wireless communication device10 is under a force (block 62).

As an example, the communication signal 32 received by the interrogationreader may include the identification of the wireless communicationdevice 10. This identification may uniquely identify a good or articleof manufacture that contains the wireless communication device 10. Inthis manner, the interrogation reader is capable of determining and/orreporting that the good is under a force. The interrogation reader 20must be designed to operate at an operating frequency that is the sameas the operating frequency of the wireless communication device 10 usingthe antenna 18 as it is under force. Various examples of applicationsthat may use the present invention are discussed below and illustratedin FIGS. 5-12.

FIG. 5 illustrates one application for use of the wireless communicationdevice 10 and antenna 18 to indicate the pressure of a tire 70. Thewireless communication device 10 is coupled to a link chain 40, and bothare placed in the inside 72 of the tire 70. The inside 72 of the tire 70is comprised of a flexible material 43, namely, rubber, that stretchesand expands when put under pressure. As the tire 70 is inflated underpressure, the antenna 18 components stretch or expand. If the tire 70 isinflated to a threshold pressure, the links 42 form a conductor toprovide an antenna 18 to the wireless communication device 10. At thisthreshold pressure, the wireless communication device 10 will be able torespond to an interrogation reader 20 communication signal 32 using thelink chain 40 as an antenna 18.

The interrogation reader 20 is designed such that its receipt ofcommunication by a wireless communication device 10 indicates that thetire 70 has been inflated to a certain pressure. Note that otherconductive elements, such as hollow conductive spheres 44, may also beused with this embodiment to form the conductor and antenna 18.

FIG. 6 illustrates another application of the present invention whereinthe wireless communication device 10 is designed to communicate with aninterrogation reader 20 when an object or load 80 is above a certainthreshold weight. The wireless communication device 10 is attached to aflexible material 43. The wireless communication device 10 is alsocoupled to a link chain 40 that is attached to the flexible material 43,like that illustrated in FIG. 2, to provide an antenna 18. However inthis embodiment, the link chain 40 is aligned in a vertical direction sothat gravity is the force applied on the flexible material 43.

If the weight of the load 80 is sufficient to pull down on and stretchthe flexible material 43 such that the links 42 form conductiveconnections with each other to form a conductor, the wirelesscommunication device 10 will be capable of responding to aninterrogation reader 20 communication signal 32 using the link chain 40as an antenna 18. In this manner, the wireless communication device 10and link chain 40 attached to the flexible material 43 form a weightindicator so that an interrogation reader 20 is capable of determiningif the load 80 is above a certain threshold weight. Again, note thatother conductive elements, such as hollow conductive spheres 44, mayalso be used with this embodiment to form the conductor.

FIG. 7 illustrates another application of the present invention whereinthe wireless communication device 10 is capable of communicating to aninterrogation reader 20 if an axle 90 rotates above a certain speed. Thewireless communication device 10 is coupled to a series of hollowconductive spheres 44 to form an antenna 18 when the hollow conductivespheres 44 form a conductor, as illustrated in FIG. 3. The wirelesscommunication device 10 and series of hollow conductive spheres 44 areattached to a flexible material 43. The axle 90 rotates in either aclockwise or counterclockwise direction. The series of hollow conductivespheres 18 is connected to the axle 90 at an attachment point 92.

As the axle 90 rotates, the centrifugal force of the rotation causes thehollow conductive spheres 44 to move outward from the axle 90 in therotation path 94. Centrifugal force is speed divided by the radius ofthe rotating object squared. If the speed of rotation and therefore thecentrifugal force goes above a certain threshold of speed, the hollowconductive spheres 44 will move apart along the shaped link 48 to formconductive connections with each other to form a conductor. In thismanner, the wireless communication device 10 and the hollow conductivespheres 44 attached to the flexible material 43 form a speed indicatorso that an interrogation reader 20 is capable of determining if the axle90 is rotating above a certain threshold speed. Again, note that otherconductive elements, such as links 42, may also be used with thisembodiment to form the conductor.

In another embodiment, the series of conductive elements, such as a linkchain 40 or series of hollow conductive spheres 44, may be used toindicate if a sufficient amount of pressure has been applied to asecurity strap. For example, the link chain 40 coupled to a wirelesscommunication device 10 may be used as a securing strap for air-cargopallets. The wireless communication device 10 cannot use the strap as anantenna 18 unless the strap has been secured with the correct amount ofpressure. An example of straps that are attached to pallets to securecargo is disclosed in co-pending U.S. patent application Ser. No.09/712,645, entitled “Wireless transport communication device andmethod,” filed on Nov. 14, 2000, and incorporated herein by reference inits entirety.

FIG. 8 illustrates another embodiment of the antenna 18 wherein a tuningring 100 is coupled to the wireless communication device 10 through thecouplings 41. A link chain 40 is attached on each side of the tuningring 100 at connection points 102. In this embodiment, two link chains40 are coupled to the tuning ring 100 to form a dipole antenna 18 whenthe link chains 40 are under a force to form conductors.

The tuning ring 100 is used to improve the connection strains betweenthe wireless communication device 10 and the link chain 40 so that aforce applied to the link chain 40 exerts force on the tuning ring 100rather than the wireless communication device 10. In addition, thetuning ring 100 allows the wireless communication device to communicateat two different operating frequencies. The tuning ring 100 always formsa conductive connection with the wireless communication device 10 toform a first antenna 18A regardless of the force, or lack thereof,applied to the flexible material 43, the link chain 40, and/or thetuning ring 100. The tuning ring 100 provides the first antenna 18A sothat the wireless communication device 10 is capable of operating at afirst operating frequency. In one embodiment, the tuning ring 100 isconstructed to resonate at around about 2.45 GHz.

If a sufficient force is exerted on the link chain 40, the individuallinks 42 form conductive connections with each other to form a second,dipole antenna 18B. The link chain 40 forms an antenna 18B that isdesigned to operate at a different, second operating frequency thandesigned for the tuning ring 100. In this manner, the wirelesscommunication device 10 is capable of communicating a second operatingfrequency if a force is exerted on the flexible material 43 and/or thelink chain 40. In one embodiment, the link chain 40 is constructed toresonate at around about 915 MHz. Again, note that other conductiveelements, such as hollow conductive spheres 44, may also be used withthis embodiment to form the conductor.

FIG. 9 illustrates another embodiment of the present invention that issimilar to the embodiment illustrated in FIG. 8. The wirelesscommunication device 10 is capable of communicating at two differentoperating frequencies. However, this embodiment does not contain thetuning ring 100. A link chain 40 is coupled to the wirelesscommunication device 10 that contains a moveable link 110 that is freeto move about. This moveable link 110 will form a conductive connectionwith adjacent links 42 in the link chain 40 if a certain threshold forceis applied to the link chain 40. The other links 42 in the link chain 40are conductively coupled to each other regardless of the force appliedto the link chain 40, or lack thereof.

The wireless communication device 10 is coupled to the link chain 40 toform a first antenna 18A of length L₁ when the moveable link 110 doesnot form a conductive connection with adjacent links 42. In this manner,the wireless communication device 10 is capable of operating at a firstoperating frequency as defined by the length L₁ and the construction ofthe first antenna 18A. In one embodiment, the length L₁ is approximately30.6 millimeters so that the link chain 40 of length L₁ resonates ataround about 2.45 GHz.

If a force is applied to the link chain 40 such that the moveable link110 forms a conductive connection with adjacent links 42 in the linkchain 40, a second antenna 18B of length L₂ is coupled to the wirelesscommunication device 10. In this manner, the wireless communicationdevice 10 is capable of operating at a second operating frequency asdefined by the length and construction of the second antenna 18B whenthe flexible material 43 and/or the link chain 40 are subject to acertain threshold force. In one embodiment, the length L₂ isapproximately 51.4 millimeters so that the link chain 40 of length L₂resonates at around about 915 MHz. Again, note that other conductiveelements, such as consecutive hollow conductive spheres 44, may also beused with this embodiment to form the conductor.

Also note that more than one moveable link 110 may be placed in the linkchain 40 so that the link chain 40 has an upper and lower frequencyrange. For example, one moveable link 110 may be placed in the linkchain 40 at a distance of 30 millimeters from the end of the link chain40 so that the link chain 40 resonates at around about 2.5 GHz when aforce is placed on the first moveable link 110. A second moveable link110 may be placed in the link chain 40 at a distance of 31 millimetersfrom the end of the link chain 40 so that the link chain 40 resonates ataround about 2.4193 GHz when a force is placed on the second moveablelink 110. In this manner, the antenna 18 formed by the link chain 40tunes itself with force.

FIG. 10 illustrates another embodiment of the present invention whereina wireless communication device 10 is capable of operating at twodifferent frequencies using two different antenna 18 lengths. A fixedconductor 14 is coupled to the wireless communication device to form afirst antenna 18A. The fixed conductor 114 has a fixed length that doesnot change as force is applied. In this embodiment, two fixed conductorsare attached to the wireless communication device 10 to form a dipoleantenna 18A.

A series of metal spheres 112 are coupled to the fixed conductors 114.The metal spheres 112 are conductively coupled to each other regardlessof force applied, or lack thereof. Hollow conductive spheres 44,illustrated in FIG. 3, are connected on the ends of the metal spheres112 such that the metal spheres 112 are connected in between the hollowconductive spheres 44 and the fixed conductor 114. The metal spheres 112are coupled to each other regardless of force. The hollow conductivespheres 44 form a conductive connection with the metal spheres 112 toform a conductor if a certain threshold force is applied to the metalspheres 112. In this manner, the wireless communication device 10 iscapable of communicating at a first operating frequency using the firstantenna 18A if a certain threshold force is not applied to the metalspheres 112, since only the fixed conductor 114 will be coupled to thewireless communication device 10.

The wireless communication device 10 will communicate at a secondoperating frequency formed by the hollow conductive spheres 44conductively coupled to the fixed conductor 114, through the metalspheres 112, to form a second, longer antenna 18B if a certain thresholdforce is applied to the metal spheres 112. Again, note that otherconductive elements, such as links 42, may also be used with thisembodiment to form the conductor.

FIGS. 11A and 11B illustrate another embodiment of the present inventionwherein an interrogation reader 20 is capable of ascertaining if awireless communication device 10 has been subjected to a certainthreshold force. A series of links 42 are coupled to the wirelesscommunication device 10, as illustrated in FIG. 3, to form the antenna18. FIG. 11A illustrates two locking mechanisms 115A, 115B in anunlocked position that are provided inline in the series of links 42attached by a linking device 113. The locking mechanisms 115A, 115B areplaced on the outside of two adjacent links 42. The locking mechanisms115A, 115B are slanted outward and are designed only to move outward andreturn to their original position, but the locking mechanisms 115A, 115Bwill not move further inward than their resting position, as illustratedin FIG. 11A.

As the links 42 are pulled outward on each side, the locking mechanisms115A, 115B move outward and the height of the locking mechanisms 115A,115B lowers. If a sufficient tension is exerted on the link 42, the link42 will exert pressure on the locking mechanism 115A, 115B, therebymoving the locking mechanisms 115A, 115B outward. Eventually, thelocking mechanisms 115A, 115B will move outward such that the links 42will clear the locking mechanisms 115A, 115B and move to their outside,as illustrated in FIG. 11B.

The locking mechanisms 115A, 115B are constructed out of a conductivematerial so that the locking mechanisms 115A, 115B form part of theconductor used by the wireless communication device 10 as an antenna 18when in a locked position. When the locking mechanisms 115A, 115B are ina locked position, the links 42, by the force of the linking device 113causing the links 42 to have force placed on them inwardly, are inconductive contact with the locking mechanisms 115A, 115B, therebyforming a conductor to be used by the wireless communication device 10as an antenna 18 for communications to an interrogation reader 20.

Since the locking mechanisms 115A, 115B only become locked when acertain threshold force is applied to the links 42, the conductor isonly formed when a certain threshold force has been applied to the links42 at least once. Once this threshold force has been applied, theconductor stays formed even if the force is released due to the lockingmechanism 115A, 115B keeping the links 42 from releasing, therebybreaking the conductivity in the conductor.

The interrogation reader 20, by receipt of communication from thewireless communication device 10 that includes the locking mechanisms115A, 115B, has knowledge that a certain threshold force has beenapplied to the links 42. If the wireless communication device 10 was notin range of the field 34 of the interrogation reader 20 at the time thethreshold force was applied to the links 42, the interrogation reader 20could still determine that the threshold force was applied to thewireless communication device 10 at some time in its past since thelocking mechanisms 115A, 115B stay locked, keeping the conductor formed.Again, note that other conductive elements, such as hollow conductivespheres 44, may also be used with this embodiment to form the conductor.

FIG. 12 illustrates a block diagram of an information reportingconfiguration for the present invention whereby information received bythe interrogation reader 20 from wireless communication devices 10 iscommunicated to other systems. The interrogation reader 20 may becoupled to a reporting system 120. This reporting system 120 may belocated in close proximity to the interrogation reader 20, and may becoupled to the interrogation reader 20 by either a wired or wirelessconnection. The reporting system 120 may be a user interface or othercomputer system that is capable of receiving information about objectsthat contain wireless communication devices 10. The information may beused to track the objects or to store information concerning the objectsin memory (not shown).

The reporting system 120 may also further communicate information fromthe wireless communication devices 10 to a remote system 122 locatedremotely from the reporting system 120 and/or the interrogation reader20. The communication between the reporting system 120 and the remotesystem 122 may be through wired communication, modem communication orother networking communication, such as the Internet. Alternatively, theinterrogation reader 20 may communicate information about the wirelesscommunication devices 10 directly to the remote system 122 rather thanfirst reporting the information through the reporting system 120.

Certain modifications and improvements will occur to those skilled inthe art upon a reading of the foregoing description. It should beunderstood that the present invention is not limited to any particulartype of component, including but not limited to the wirelesscommunication device 10 and its components, the interrogation reader 20and its components, the link chain 40, the links 42, the flexiblematerial 43, the hollow conductive sphere 44, the shaped link 48, thetire 70, the load 80, the axle 90, the tuning ring 100, the moveablelink 110, the metal spheres 112, the locking mechanisms 115A, 115B, thelinking device 113, the fixed conductor 114, the reporting system 120,and the remote system 122. For the purposes of this application, couple,coupled, or coupling is defined as either a direct connection or areactive coupling. Reactive coupling is defined as either capacitive orinductive coupling.

One of ordinary skill in the art will recognize that there are differentmanners in which these elements can accomplish the present invention.The present invention is intended to cover what is claimed and anyequivalents. The specific embodiments used herein are to aid in theunderstanding of the present invention, and should not be used to limitthe scope of the invention in a manner narrower than the claims andtheir equivalents.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the invention.

1. A method of wirelessly communicating information, the methodcomprising: placing a series of conductive elements under a thresholdforce, wherein the conductive elements couple together to form aconductor that is configured to resonate at a first frequency; andcommunicating information at the first frequency using the series ofconductive elements as a first antenna while the series of conductiveelements is configured to resonate at the first frequency, wherein priorto placing the series of conductive elements under the threshold force,the series of conductive elements are not coupled together to form aconductor configured to resonate at the first frequency.
 2. The methodof claim 1, wherein said placing a series of conductive elements under athreshold force comprises stretching the series of conductive elements.3. The method of claim 1, wherein said placing a series of conductiveelements under a threshold force comprises compressing the series ofconductive elements.
 4. The method of claim 1, wherein said placing aseries of conductive elements under a threshold force comprises rotatingthe series of conductive elements.
 5. The method of claim 1, wherein theseries of conductive elements is coupled to a tuning ring, and whereinthe method further comprises communicating information at a secondfrequency using the tuning ring as a second antenna.
 6. The method ofclaim 1, wherein said placing a series of conductive elements under athreshold force further comprises: placing the series of conductiveelements under a first force to form a first conductor length configuredto operate at the first frequency in a first mode of operation; andplacing the series of conductive elements under a second force to form asecond conductor length configured to operate at a second frequency in asecond mode of operation.
 7. The method of claim 6, wherein said placinga series of conductive elements under a threshold force furthercomprises: placing the first force on a first set of conductive elementsin the series of conductive elements; and placing the second force on asecond set of conductive elements in the series of conductive elementsthat is located adjacent to the first set of conductive elements.
 8. Themethod of claim 1, further comprising locking the series of conductiveelements placed under the threshold force into a conducting position. 9.The method of claim 1, wherein said placing a series of conductiveelements under a threshold force comprises changing a dimension of theseries of conductive elements to expand or contract in relation totemperature.
 10. The method of claim 1, wherein said communicatinginformation comprises reporting threshold force information from awireless communication device that is interrogated by an interrogationdevice.
 11. The method of claim 1, further comprising communicating theinformation at a second frequency using a conductive support elementcoupled between the series of conductive elements and a wirelesscommunication device if the series of conductive elements is not underthe threshold force.
 12. The method of claim 1, wherein the series ofconductive elements is a series of hollow conductive elements connectedby conductive links that couple the conductive elements together ifunder the threshold force.
 13. A method of wirelessly communicatinginformation, the method comprising: placing a first conductive componentcoupled to a wireless communication component under a first thresholdforce, wherein the first conductive component is comprised of aplurality of conductive elements that are configured to couple togetherto form a conductor that resonates at a first frequency if placed underthe first threshold force, and if the plurality of conductive elementsare not placed under the first threshold force, the plurality ofconductive elements are not coupled together to form a conductor thatresonates at the first frequency; communicating information at the firstfrequency using the first conductive component as an antenna; placing asecond conductive component coupled to the wireless communicationcomponent under a second threshold force, wherein the second conductivecomponent is configured to resonate at a second frequency if placedunder the second threshold force; and communicating information at thesecond frequency using the second conductive component as an antenna.14. The method of claim 13, wherein the first conductive component is afirst series of conductive elements configured to couple together andform a conductor that resonates at the first frequency if placed underthe first threshold force.
 15. The method of claim 14, wherein thesecond conductive component is a conductive support element that couplesthe first series of conductive elements to the wireless communicationcomponent and reduces strain on the wireless communication componentcaused by the series of conductive elements.
 16. The method of claim 14,wherein the second conductive component is a second series of conductiveelements configured to couple together and form a conductor thatresonates at the second frequency if placed under the second thresholdforce.
 17. A device, comprising: a wireless communication component; anda series of conductive elements coupled to the wireless communicationcomponent and configured such that, if placed under a threshold force,the conductive elements in the series of conductive elements coupletogether to form a conductor that resonates at a first frequency forcommunicating information from the wireless communication component,wherein, if not placed under the threshold force, the conductiveelements are not coupled together to form a conductor that resonates atthe first frequency.
 18. The device of claim 17, further configured suchthat, if the conductive elements are not placed under the thresholdforce, the conductive elements do not form a conductor that resonates atthe first frequency.
 19. The device of claim 17, further comprising aconductive support element that couples the series of conductiveelements to the wireless communication component.
 20. The device ofclaim 19, wherein the conductive support element is configured tocommunicate information from the wireless communication component at asecond frequency if the conductive elements are not placed under thethreshold force.
 21. The device of claim 17, wherein the conductiveelements are hollow conductive elements connected by moveable conductivelinks configured to couple the conductive elements together to form theconductor if placed under the threshold force.
 22. A device, comprising:a wireless communication component; a first conductive component coupledto the wireless communication component, wherein the first conductivecomponent is comprised of a plurality of conductive elements that areconfigured to couple together to form a conductor that resonates at afirst frequency for communicating information from the wirelesscommunication component if a first threshold force is applied to thedevice, and if the first threshold force is not applied to the device,the plurality of conductive elements are not coupled together to form aconductor that resonates at the first frequency; and a second conductivecomponent coupled to the wireless communication component, wherein thesecond conductive component is configured to resonate at a secondfrequency for communicating information from the wireless communicationcomponent if a second threshold force is applied to the device.
 23. Thedevice of claim 22, wherein the first conductive component is a firstseries of conductive elements that are configured to couple together andform a conductor that resonates at the first frequency if placed underthe first threshold force.
 24. The device of claim 23, wherein thesecond conductive component is a conductive support element that couplesthe first series of conductive elements to the wireless communicationcomponent and reduces strain on the wireless communication componentcaused by the series of conductive elements.
 25. The device of claim 23,wherein the second conductive component is a second series of conductiveelements that are configured to couple together and form a conductorthat resonates at the second frequency if placed under the secondthreshold force.
 26. A method comprising: coupling a first conductivecomponent to a wireless communication device, wherein the firstconductive component includes a plurality of conductive elements thatare configured to couple together to form a conductor that resonates ata first frequency for communicating information from the wirelesscommunication device if placed under a first threshold force, and if theplurality of conductive elements are not placed under the firstthreshold force, the plurality of conductive elements are not coupledtogether to form a conductor that resonates at the first frequency; andcoupling a second conductive component to the wireless communicationdevice, wherein the second conductive component is configured toresonate at a second frequency for communicating information from thewireless communication device if placed under a second threshold force,wherein the first and second conductive components are configured to notresonate at the respective first and second frequencies if the first andsecond conductive components are not placed under the respective firstand second threshold forces.
 27. The method of claim 26, furthercomprising communicating information at the first frequency using thefirst conductive component as an antenna while the first conductivecomponent is placed under the first threshold force.
 28. The method ofclaim 26, further comprising communicating information at the secondfrequency using the second conductive component as an antenna while thesecond conductive component is placed under the second threshold force.29. The method of claim 26, further comprising: coupling a conductivesupport element to the wireless communication device; and coupling thefirst conductive component to the conductive support element, whereinthe conductive support element is configured to resonate at a thirdfrequency for communicating information from the wireless communicationdevice if the first conductive component is not placed under the firstthreshold force.